EXTREMOPHILES as Astrobiological Models. Группа авторов

greater depths the descending water boils and provides steam and heat so that (3) salts continue to slowly dissolve, rise with steam and deposit as evaporites on a cooler nearby wall, ceiling or as in this model, a shelf. (Image credit: the authors).

      Models of the sulfur and ammonia oxidizing environments are available in a previous study [1.3].

1.7 Conclusions

      The worldwide abundance of fumaroles compared to hot springs make this an ideal choice as a habitat for early development of life on Earth. These primitive steam habitats characterized by two extreme physical features, low pH and high temperature, typically flourish with Archaea. The fact that these organisms seem to have persisted from the earliest times argues that they may represent the type of living organism that could have evolved else-where beyond planet Earth. Steam caves/vents, while limited in diversity [1.7], represent and remain a rich and potentially useful and reliable source for isolation of unknown and unexplored life forms.

Acknowledgments

We thank the following National Park Service members for assistance with access to collections; Michael Magnuson, Wildlife Biologist, Lassen Volcanic National Park; Rhonda Loh, Chief of Natural Resources Management and Keola Awong, Cultural Specialist and Native Hawaiian Liaison for facilitating our collections of fumaroles and supporting our research efforts in Hawai’i Volcanoes National Park. Jeff Sutton and Aaron Pietruszka, US Geological Survey, offered guidance on the Geology/Geochemistry of our collection areas. Benno Spingler prepared Figure 1.1; Xzayla Zabiti and Anthony Correy provided ideas and participated in the design and construction of the steam collector. We thank our graduate students, Dean Ellis, Courtney Benson, Kate Wall, and Jenny Cornell, and undergraduates, Christa Anderson and Wendy Gutierrez. The authors acknowledge the assistance of Steve Barlow, and use of equipment at the San Diego State University Electron Microscopy Facility acquired by NSF Instrumentation grant DBI-0959908, SB Barlow. Ingrid Niesman, Director of the SDSU Electron Microscope Laboratory facilitated the SEM work. Generous contributions of Schering-Plough Biopharma assisted this study.

References

      1.1. Benson, C.A., Bizzoco, R.W., Lipson, D.A., Kelley, S.T., Microbial diversity in nonsulfur, sulfur and iron geothermal steam vents. FEMS Microbiol. Ecol., 76, 1, 74–88, 2011.

      1.2. Bizzoco, R.L.W. and Kelley, S.T., Microbial diversity in acidic high-temperature steam vents [Chapter 30], in: Polyextremophiles: Life under Multiple Forms of Stress [Volume 27 in the series: Cellular Origin, Life in Extreme Habitats and Astrobiology, series editor: Joseph Seckbach], J. Seckbach, A. Oren, H. Stan-Lotter (Eds.), pp. 315–332, Springer, Dordrecht, 2013.

      1.3. Bizzoco, R.L.W. and Kelley, S.T., Geothermal steam vents of Hawai’i [Chapter 2], in: Model Ecosystems in Extreme Environments [MEET], Volume 2 in the series: Astrobiology: Exploring Life on Earth and Beyond, P. Rampelotto, J. Seckbach, R. Gordon, J. Seckbach, P. Rampelotto (Eds.), pp. 23–40, Imperial College Press, UK, 2019.

      1.4. Brochier-Armanet, C., Boussau, B., Gribaldo, S., Forterre, P., Mesophilic crenarchaeota: Proposal for a third archaeal phylum, the Thaumarchaeota. Nat. Rev. Microbiol., 6, 3, 245– 252, 2008.

      1.5. Brock, T.D., Thermophilic Microorganisms and Life at High Temperatures, Springer, New York, 1978.

      1.6. Chemtob, S.M., Jolliff, B.L., Arvidson, R.E., Si-and Ti-rich surface coatings on Hawaiian basalt and implications for remote sensing on Mars, in: Lunar Planetary Science 37th Conference, 2006.

      1.7. Cockell, C.S., Harrison, J.P., Stevens, A.H., Payler, S.J., Hughes, S.S., Kobs Nawotniak, S.E., Brady, A.L., Elphic, R.C., Haberle, C.W. et al., A low-diversity microbiota inhabits extreme terrestrial basaltic terrains and their fumaroles: Implications for the exploration of Mars. Astrobiology, 19, 3, 284–299, 2019.

      1.8. Ellis, D.G., Bizzoco, R.W., Kelley, S.T., Halophilic Archaea determined from geothermal steam vent aerosols. Environ. Microbiol., 10, 6, 1582–1590, 2008.

      1.9. Grogan, D.W., Phenotypic characterization of the Archaebacterial genus Sulfolobus: Comparison of five wild-type strains. J. Bacteriol., 171, 12, 6710–6719, 1989.

      1.10. Hughes, S.S., Haberle, C.W., Kobs Nawotniak, S.E., Sehlke, A., Garry, W.B., Elphic, R.C., Payler, S.J., Stevens, A.H., Cockell, C.S., Brady, A.L. et al., Basaltic terrains in Idaho and Hawai’i as planetary analogs for Mars geology and astrobiology. Astrobiology, 19, 3, 260– 283, 2019.

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1.12. King, G.M., Chemolithotrophic bacteria: Distributions, functions and significance in volcanic environments. Microbes Environ., 22, 4, 309–319, 2007.

      1.13. Nordstrom, D.K., Ball, J.W., McCleskey, R.B., Ground water to surface water: Chemistry of thermal outflows in Yellowstone National Park, in: Geothermal Biology and Geochemistry in Yellowstone National Park, W.P. Inskeep and T.R. McDermott (Eds.), pp. 73–94, Montana State University Publications, Bozeman, MT, 2005.

      1.14. Stahl, D.A. and de la Torre, J.R., Physiology and diversity of ammonia-oxidizing Archaea. Annu. Rev. Microbiol., 66, 83–101, 2012.

      1.15. Stieglmeier, M., Alves, R.J.E., Schleper, C., The Phylum Thaumarchaeota, in: The Prokaryotes, E. Rosenberg, E.F. DeLong, S. Lory, E. Stackebrandt, F. Thompson (Eds.), pp. 347–362, Springer-Verlag Berlin, Heidelberg, 2014.

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      1 * Corresponding author: [email protected]

      2 Richard L. Weiss Bizzoco: https://www.researchgate.net/profile/Richard_Bizzoco

      3 Scott T. Kelley: https://scholar.google.com/citations?user=oHXnsCEAAAAJ&hl=en

      2

      Rio Tinto: An Extreme Acidic Environmental Model of Astrobiological Interest

       Ricardo Amils 1,2* and David Fernández-Remolar3,4

       ¹ Centro de Astrobiología (CAB, CSIC-INTA), Torrejón de Ardoz, Spain

       ² Centro de Biología Molecular Severo Ochoa (CBMSO, CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain

       ³ State Key of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau SAR, People’s Republic of China

       ⁴ CNSA Macau Center for Space Exploration and Science, Macau SAR, People´s Republic of China

       Abstract

      Among extremophiles, acidophiles are of special interest because their chemolithotrophic metabolism obtains energy from reduced minerals, thus creating the extreme acidic conditions in which they thrive. Rio Tinto is a 92 km long extreme acidic environment, which is the product of the metabolic activity of chemolithotrophic microorganisms thriving in the high concentration of metal sulfidic minerals existing in the Iberian Pyrite Belt. An extensive geomicrobiological characterization of the Tinto